Method and system for configurable differential or single-ended signaling in an integrated circuit

ABSTRACT

Aspects of a method and system for configurable differential or single-ended signaling in an integrated circuit. In this regard, a balun comprising one or more loops fabricated in a plurality of metal layers in an integrated circuit may enable conversion between unbalanced and balanced signals. In this regard, balanced signal output by a power amplifier may be converted to a balanced signal for transmission via an antenna. Similarly, an unbalanced signal received by an antenna may be converted to a balanced signal for amplification by an amplifier with a balanced input. The loops may be fabricated in transmission line media such as microstrip and/or stripline. The loops may comprise ferromagnetic material which may be deposited on and/or within the IC. Signals converted via the balun may be in the 61 GHz-61.5 GHz ISM band.

CROSS-REFERENCE TO RELATED APPLICATIONS/INCORPORATION BY REFERENCE

This patent application is a continuation of U.S. application Ser. No.12/056,525, filed Mar. 27, 2008, which is incorporated herein in itsentirety for all purposes.

FIELD OF THE INVENTION

Certain embodiments of the invention relate to signal processing. Morespecifically, certain embodiments of the invention relate to a methodand system for configurable differential or single-ended signaling in anintegrated circuit.

BACKGROUND OF THE INVENTION

Mobile communications have changed the way people communicate and mobilephones have been transformed from a luxury item to an essential part ofevery day life. The use of mobile phones is today dictated by socialsituations, rather than hampered by location or technology. While voiceconnections fulfill the basic need to communicate, and mobile voiceconnections continue to filter even further into the fabric of every daylife, the mobile Internet is the next step in the mobile communicationrevolution. The mobile Internet is poised to become a common source ofeveryday information, and easy, versatile mobile access to this datawill be taken for granted.

As the number of electronic devices enabled for wireline and/or mobilecommunications continues to increase, significant efforts exist withregard to making such devices smaller and lighter. In this regard,designers find themselves in a never ending quest to include morefunctionality in less space. However, shrinking device and technologysizes leads to a multitude of design issues.

Further limitations and disadvantages of conventional and traditionalapproaches will become apparent to one of skill in the art, throughcomparison of such systems with some aspects of the present invention asset forth in the remainder of the present application with reference tothe drawings.

BRIEF SUMMARY OF THE INVENTION

A system and/or method for configurable differential or single-endedsignaling in an integrated circuit, substantially as shown in and/ordescribed in connection with at least one of the figures, as set forthmore completely in the claims.

These and other advantages, aspects and novel features of the presentinvention, as well as details of an illustrated embodiment thereof, willbe more fully understood from the following description and drawings.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a block diagram illustrating an exemplary wireless device, inaccordance with an embodiment of the invention.

FIG. 2 is a diagram of an exemplary balun transformer, in accordancewith an embodiment of the invention.

FIG. 3 is a diagram illustrating an exemplary multi-layer balun, inaccordance with an embodiment of the invention.

FIG. 4 is a diagram illustrating a cross-sectional view of a balunfabricated in an integrated circuit, in accordance with an embodiment ofthe invention.

FIG. 5 is a flow chart illustrating exemplary steps for convertingbetween unbalanced and balanced signaling via an integrated balun, inaccordance with an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Certain embodiments of the invention may be found in a method and systemfor configurable differential or single-ended signaling in an integratedcircuit. In this regard, a balun comprising one or more loops fabricatedin a plurality of metal layers in an integrated circuit may enableconversion between unbalanced and balanced signals. In this regard,balanced signal output by a power amplifier may be converted to abalanced signal for transmission via an antenna. Similarly, anunbalanced signal received by an antenna may be converted to a balancedsignal for amplification by an amplifier with a balanced input. Theloops may be fabricated in transmission line media such as microstripand/or stripline. The loops may comprise ferromagnetic material whichmay be deposited on and/or within the IC. Signals converted via thebalun may be in the 61 GHz-61.5 GHz ISM band.

FIG. 1 is a block diagram illustrating an exemplary wireless device, inaccordance with an embodiment of the invention. Referring to FIG. 1,there is shown a wireless device 120 that may comprise an RF transceiver123, a digital baseband processor 129, a processor 425, and a memory127. The transceiver 123 may comprise a receiver 123 a and a transmitter123 b. An antenna 121 may be communicatively coupled to the RFtransceiver 123 via the balun 112. The wireless device 120 may beoperated in a system, such as the cellular network and/or digital videobroadcast network, for example.

In an exemplary embodiment of the invention, the antenna 121 maycomprise one or more antenna elements which may be coupled and/ordecoupled via one or more switching elements. In this regard, theantenna 121 may be configured based on factors comprising frequency,polarization, and/or gain. In another exemplary embodiment of theinvention, the antenna 121 may be a phased array antenna. In thisregard, the directivity of the antenna may be controlled by adjustingthe phase(s) of signals communicatively coupled to the antenna.

The RF receiver 123 a may comprise suitable logic, circuitry, and/orcode that may enable processing of received RF signals. The RF receiver123 a may enable receiving RF signals in a plurality of frequency bands.For example, the RF receiver 123 a may enable receiving signals inextremely high frequency (e.g., 60 GHz) bands. The receiver 123 a may beenabled to receive, filter, amplify, down-convert, and/or perform analogto digital conversion. The RF receiver 123 a may down convert a receivedRF signal. In this regard, the RF receiver 123 a may perform direct downconversion of the received RF signal to a baseband or may convert thereceived RE signal to an intermediate frequency (IF). In variousembodiments of the invention, the receiver 123 a may perform quadraturedown-conversion where in-phase components and quadrature phasecomponents may be processed in parallel. The receiver 123 a may beenabled to receive signals via the balun 112, which may be configurableand provide a means for converting between differential and single endedsignaling. In various embodiments of the invention, the wireless device120 may comprise a plurality of the receivers 123 a and may thus supportmultiple frequency bands and or simultaneous reception of signals in thesame frequency band.

The digital baseband processor 129 may comprise suitable logic,circuitry, and/or code that may enable processing and/or handling ofbaseband signals. In this regard, the digital baseband processor 129 mayprocess or handle signals received from the RF receiver 123 a and/orsignals to be transferred to the RF transmitter 123 b, when the RFtransmitter 123 b is present, for transmission to the network. Thedigital baseband processor 129 may also provide control and/or feedbackinformation to the RF receiver 123 a and to the RF transmitter 123 bbased on information from the processed signals. In this regard, thebaseband processor 129 may provide one or more control signals forconfiguring the balun 112 via one or more switching elements. Thedigital baseband processor 129 may communicate information and/or datafrom the processed signals to the processor 425 and/or to the memory127. Moreover, the digital baseband processor 129 may receiveinformation from the processor 425 and/or to the memory 127, which maybe processed and transferred to the RF transmitter 123 b fortransmission to the network.

The RF transmitter 123 b may comprise suitable logic, circuitry, and/orcode that may enable processing of RF signals for transmission. Thetransmitter 123 b may be enabled to transmit signals via the balun 112,which may be configurable and provide a means for converting betweensingle ended (unbalanced) and differential (balanced) signaling. The RFtransmitter 123 b may enable transmission of RF signals in a pluralityof frequency bands. For example, the RF transmitter 123 b may enabletransmitting signals in cellular frequency bands. Each frequency bandsupported by the RF transmitter 123 b may have a corresponding front-endcircuit for handling amplification and up conversion operations, forexample. In this regard, the RF transmitter 123 b may be referred to asa multi-band transmitter when it supports more than one frequency band.In another embodiment of the invention, the wireless device 120 maycomprise more than one RF transmitter 123 b, wherein each of the RFtransmitters 123 b may be a single-band or a multi-band transmitter.

In various embodiments of the invention, the RF transmitter 123 b mayperform direct up conversion of the baseband signal to an RF signal. Insome instances, the RF transmitter 123 b may enable digital-to-analogconversion of the baseband signal components received from the digitalbaseband processor 129 before up conversion. In other instances, the RFtransmitter 123 b may receive baseband signal components in analog form.

The processor 425 may comprise suitable logic, circuitry, and/or codethat may enable control and/or data processing operations for thewireless device 120. The processor 425 may be utilized to control atleast a portion of the RF receiver 123 a, the RF transmitter 123 b, thedigital baseband processor 129, and/or the memory 127. In this regard,the processor 425 may generate at least one signal for controllingoperations within the wireless device 120. In this regard, the basebandprocessor 129 may provide one or more control signals for configuringthe balun 112 via one or more switching elements. The processor 425 mayalso enable executing of applications that may be utilized by thewireless device 120. For example, the processor 425 may executeapplications that may enable displaying and/or interacting with contentreceived via cellular transmission signals in the wireless device 120.

The memory 127 may comprise suitable logic, circuitry, and/or code thatmay enable storage of data and/or other information utilized by thewireless device 120. For example, the memory 127 may be utilized forstoring processed data generated by the digital baseband processor 129and/or the processor 425. The memory 127 may also be utilized to storeinformation, such as configuration information, that may be utilized tocontrol the operation of at least one block in the wireless device 120.For example, the memory 127 may comprise information necessary toconfigure the balun 112. In this regard, the memory may store controland/or configuration information for configuring the windings ratio ofthe transformer 112 via one or more switching elements.

In operation, a wireless signal may be received via the antenna 121 andconveyed to the transceiver 123 via the balun 112 fabricated in one ormore metal layers of an integrated circuit in the wireless device 120.In this regard, the balun may convert the unbalanced received signalfrom the antenna 121 to a balanced signal which may be processed by thetransceiver. Similarly, a signal transmitted by transceiver 123 may becoupled to the antenna 121 via the balun 112 fabricated in one or moremetal layers of an integrated circuit in the wireless device 120. Inthis regard, the balun 112 may convert a balanced signal output by apower amplifier in the transceiver 123 into an unbalanced signal fortransmission via the antenna 121.

FIG. 2 is a diagram of an exemplary balun, in accordance with anembodiment of the invention. Referring to FIG. 2, there is shown a balun200, an antenna capacitor 207, an antenna 121, and switches 211A and211B. The balun 200 may comprise input terminals 201A and 201B, a DCbias tap 207, and output terminals 203 and 205.

The antenna 121 may be as described with respect to FIG. 1.

The antenna capacitor 207 may enable improved impedance matching betweenthe antenna 121 and the output impedance of the power amplifier in thetransceiver 152 described with respect to FIG. 1. The switches 211B and211B may comprise microelectromechanical system (MEMS) switches or CMOStransistor switches on an integrated circuit, for example.

In operation, an RF signal to be transmitted may be communicated from adifferential output power amplifier to the balanced inputs 201A and 201Bof the balun 200. The unbalanced output signal may be communicated tothe antenna 209 for transmission. In an embodiment of the invention, theantenna capacitor 207 may be configurable to adjust the impedancematching for different frequencies or different antennas in instanceswhere more than one antenna may be utilized.

In an exemplary embodiment of the invention, an unbalanced signalsuitable for transmission may be communicatively coupled to the terminal201 a. Accordingly, the switch 211B may be configured such that theinput terminal 201 a may be coupled to the antenna 121. Additionally theswitch 211 a may communicatively couple the terminal 201 b to ground. Inthis manner, the balun 112 may be effectively bypassed.

In an exemplary embodiment of the invention, an unbalanced signal whichmay be unsuitable for transmission via the antenna 121 may becommunicatively coupled to the input terminal 201 a. Accordingly, theswitch 211 a may communicatively couple the input terminal 201 b toground and the switch 211 b may communicatively couple the outputterminal 203 to the antenna 121. In this manner, the balun 112 mayprovide impedance matching and/or otherwise condition the unbalancedsignal for transmission via the antenna 121.

In an exemplary embodiment of the invention, a balanced signal may becommunicatively coupled to the input terminals 201. Accordingly, theswitch 211 a may be open and the switch 211 b may communicatively couplethe output terminal 203 to the antenna 121. In this manner, the balancedsignal may be converted to an unbalanced signal suitable fortransmission via the antenna 121.

In various other embodiments of the invention, a signal may be receivedvia the antenna 121 and the switches 211 a and 211 b may be configuredto impedance match the received signal to downstream circuitry, convertthe received signal to a differential representation, or bypass thebalun 112.

FIG. 3 is a diagram illustrating an exemplary multi-layer balun, inaccordance with an embodiment of the invention. Referring to FIG. 3,there is shown the balun 200 comprising a plurality of conductive loops304 a, 306 a, 304 b, 306 b, and 304 c arranged in a vertical stack andcommunicatively coupled via a plurality of vias 302. The input terminals201A and 201B, the DC bias tap 207, and the output terminals 203 and 205may be as described with respect to FIG. 2.

In an exemplary embodiment of the invention, a primary winding of thebalun 200 may comprise the loops 304 a, 304 b, and 304 c and a secondarywinding may comprise the loops 306 a and 306 b. In this regard, theintegrated circuit may comprise at least five metal layers, as describedwith respect to FIG. 4. Also, in various embodiments of the invention,the integrated circuit may be communicatively coupled to a multi-layerpackage. In this regard, the integrated circuit may be coupled to thepackage via a flip-chip bonding technique to reduce stray impedances.Additionally, in various embodiments of the invention, ferromagneticmaterial may be deposited in and/or on the integrated circuit 200 toimprove the magnetic coupling of the loops in the balun 200.

In an exemplary embodiment of the invention, the balun 200 may be suitedfor processing signals in the 61-61.5 GHZ industrial, scientific, andmedical (ISM) band. In this regard, the inductive loops 304 and 306 maybe fabricated utilizing transmission line media such as stripline and/ormicrostrip.

In operation, a differential RF signal may be converted to a singleended signal by the balun 200. The differential signal may becommunicatively coupled to the input terminals 201 a and 201 b via oneor more metal layers and/or vias in the integrated circuit, as describedwith respect to FIG. 3.

FIG. 4 is a diagram illustrating a cross-sectional view of a balunfabricated in an integrated circuit, in accordance with an embodiment ofthe invention. Referring to FIG. 4, there is shown an integrated circuit200, metal layers 402, 404, 406, 408 and 410, and interconnect 415.There is also shown the + and − balanced inputs 201A and 201B, theunbalanced output 203, the ground output 205, and the DC bias tap 207.

The integrated circuit 200 may, for example, comprise the transceiver123 described with respect to FIG. 1, or may also comprise any otherintegrated circuit within the wireless device 120 that may requireconversion between single ended and differential signaling. The chip 401may be bump-bonded or flip-chip bonded to a multi-layer package via oneor more solder balls. In this manner, wire bonds coupling the chip 200to a multi-layer package may be eliminated, reducing and/or eliminatingstray inductances due to wire bonds. In addition, the thermalconductance out of the chip 200 may be greatly improved utilizing solderballs and thermal epoxy. Thermal epoxy may be electrically insulatingbut thermally conductive to allow for thermal energy to be conducted outof the chip 200 to the much larger thermal mass of a multilayer package.

The loops 304 a, 306 a, 304 b, 306 b, and 304 c, as described withrespect to FIG. 3, may be fabricated in the metal layers 402, 404, 406,408, and 410, respectively. The metal layers may comprise transmissionline media such as strip-line and/or microstrip. In an exemplaryembodiment of the invention, the metal layers 402, 404, 406, 408, and410 may comprise ferromagnetic and/or ferrimagnetic materials utilizedto improve magnetic coupling magnetic devices such as transformers,inductors, baluns, isolators, circulators, and gyrators. The magneticmaterials may be deposited on the top, bottom and/or embedded within theintegrated circuit 200.

The interconnects 415 may comprise traces embedded in and/or depositedon the integrated circuit 200 that may be utilized as electricallyconductive paths in the balun 200 and also to/from the balun 200 andother portions of the integrated circuit 200. Various embodiments of theinvention may comprise fewer and/or additional interconnects 415, andthus the invention may not be limited to the number shown in FIG. 4.

In an exemplary embodiment of the invention, the integrated circuit 200may comprise an RF front end, such as the RF transceiver 123, describedwith respect to FIG. 1, and may be utilized to transmit and receive RFsignals. Additionally, the balun 200 may be configured, via one or moreswitches as described with respect to FIG. 2, to perform differential tosingle ended conversion. For example, a balanced signal from a poweramplifier may be communicatively coupled to the input terminals 201 aand 201 b via the metal layer 402 and/or one or more interconnects 415.Accordingly, the balun 200 may convert the balanced signal into anunbalanced signal and may output the unbalanced signal to an antenna byway of the metal layers 404 and 408 and one or more interconnects 415.

FIG. 5 is a flow chart illustrating exemplary steps for convertingbetween unbalanced and balanced signaling via an integrated balun, inaccordance with an embodiment of the invention. Referring to FIG. 5,subsequent to start step 502, the exemplary steps may advance to step504. In step 504, the balun 200 of FIG. 2 may be configured via one ormore switching elements. For example, the balun 20 may be configuredbased on whether signals are to be received or transmitted via theantenna 121. In an exemplary embodiment of the invention, the balun 200may communicatively couple the antenna 121 to a unbalanced input of alow noise amplifier for reception and to a balanced output of a poweramplifier for transmission. Subsequent to step 504, the exemplary stepsmay advance to step 506. In step 506, a signal may be transmitted and/orreceived via the balun 200 and an associated antenna.

Aspects of a method and system for configurable differential orsingle-ended signaling in an integrated circuit. In this regard, abalun, such as the balun 112, comprising one or more loops fabricated ina plurality of metal layers in an integrated circuit, such as the IC200, may enable conversion between unbalanced and balanced signals. Inthis regard, balanced signal output by a transmitter, such as thetransmitter 123 a, may be converted to a balanced signal fortransmission via an antenna, such as the antenna 121. Similarly, anunbalanced signal received by the antenna 121 may be converted to abalanced signal for amplification by a receiver, such as the receiver123 b, with a balanced input. The loops may be fabricated intransmission line media such as microstrip and/or stripline. The loopsmay comprise ferromagnetic material which may be deposited on and/orwithin the IC. Signals converted via the balun may be in the 61 GHz-61.5GHz ISM band.

Another embodiment of the invention may provide a machine-readablestorage, having stored thereon, a computer program having at least onecode section executable by a machine, thereby causing the machine toperform the steps as described herein for configurable differential orsingle-ended signaling in an integrated circuit.

Accordingly, the present invention may be realized in hardware,software, or a combination of hardware and software. The presentinvention may be realized in a centralized fashion in at least onecomputer system, or in a distributed fashion where different elementsare spread across several interconnected computer systems. Any kind ofcomputer system or other apparatus adapted for carrying out the methodsdescribed herein is suited. A typical combination of hardware andsoftware may be a general-purpose computer system with a computerprogram that, when being loaded and executed, controls the computersystem such that it carries out the methods described herein.

The present invention may also be embedded in a computer programproduct, which comprises all the features enabling the implementation ofthe methods described herein, and which when loaded in a computer systemis able to carry out these methods. Computer program in the presentcontext means any expression, in any language, code or notation, of aset of instructions intended to cause a system having an informationprocessing capability to perform a particular function either directlyor after either or both of the following: a) conversion to anotherlanguage, code or notation; b) reproduction in a different materialform.

While the present invention has been described with reference to certainembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted withoutdeparting from the scope of the present invention. In addition, manymodifications may be made to adapt a particular situation or material tothe teachings of the present invention without departing from its scope.Therefore, it is intended that the present invention not be limited tothe particular embodiment disclosed, but that the present invention willinclude all embodiments falling within the scope of the appended claims.

1. A method for signal processing, the method comprising: receiving oneof an unbalanced signal and a balanced signal; if the unbalanced signalis received, utilizing one or more switches to select between: balancingthe unbalanced signal via a configurable balun, wherein the configurablebalun comprises a plurality of inductive loops fabricated in a pluralityof metal layers of an integrated circuit; and bypassing the configurablebalun such that the unbalanced signal remains unbalanced; and if thebalanced signal is received, unbalancing the balanced signal via theconfigurable balun.
 2. The method according to claim 1, wherein thebalanced signal is received from an amplifier in the integrated circuit.3. The method according to claim 2, comprising transmitting theunbalanced signal via an antenna communicatively coupled to the balun.4. The method according to claim 1, wherein the unbalanced signal isreceived via an antenna communicatively coupled to the integratedcircuit.
 5. The method according to claim 1, wherein ferromagneticmaterial is deposited on and/or within the integrated circuit, and theferromagnetic material improves magnetic coupling in the balun.
 6. Themethod according to claim 1, comprising converting, via said balun,signals in the 61 GHz-61.5 GHz industrial, scientific, and medicalfrequency band.
 7. The method according to claim 1, wherein theinductive loops are fabricated in transmission line media.
 8. The methodaccording to claim 7, wherein the transmission line media comprisesmicrostrip.
 9. The method according to claim 7, wherein the transmissionline media comprises stripline.
 10. A system for signal processing, thesystem comprising: a configurable balun comprising a plurality ofinductive loops fabricated in a plurality of metal layers of anintegrated circuit; and a circuit that enables selection, via one ormore switches, between: unbalancing a balanced signal via theconfigurable balun; balancing an unbalanced signal via the configurablebalun; and bypassing the configurable balun such that the unbalancedsignal remains unbalanced.
 11. The system according to claim 10, whereinthe circuit enables conversion of a balanced signal output by anamplifier in the integrated circuit to a unbalanced signal.
 12. Thesystem according to claim 11, wherein the unbalanced signal istransmitted via an antenna.
 13. The system according to claim 10,wherein the circuits enables conversion of an unbalanced signal,received via an antenna communicatively coupled to the integratedcircuit, to a balanced signal.
 14. The system according to claim 10,wherein the inductive loops comprise ferromagnetic material.
 15. Thesystem according to claim 10, wherein ferromagnetic material isdeposited on and/or within the integrated circuit, and the ferromagneticmaterial improves magnetic coupling in the balun.
 16. The systemaccording to claim 10, wherein the circuit enables converting signals inthe 61 GHz-61.5 GHz industrial, scientific, and medical frequency band.17. The system according to claim 10, wherein the inductive loops arefabricated in transmission line media.
 18. The system according to claim17, wherein the transmission line media comprises microstrip.
 19. Thesystem according to claim 17, wherein the transmission line mediacomprises stripline.
 20. An integrated circuit for signal processing,the integrated circuit comprising: an amplifier operable to generate oneof an unbalanced signal and a balanced signal; a configurable baluncoupled to the amplifier and comprising a plurality of inductive loopsfabricated in a plurality of metal layers of the integrated circuit; anda circuit that enables selection, via one or more switches, between:unbalancing the balanced signal via the configurable balun; balancingthe unbalanced signal via the configurable balun; and bypassing theconfigurable balun such that the unbalanced signal remains unbalanced.